ReferenceCountedArray.h

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/*
  ==============================================================================
 
   This file is part of the Water library.
   Copyright (c) 2016 ROLI Ltd.
   Copyright (C) 2017 Filipe Coelho <falktx@falktx.com>
 
   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/
 
   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.
 
   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.
 
  ==============================================================================
*/
 
#ifndef WATER_REFERENCECOUNTEDARRAY_H_INCLUDED
#define WATER_REFERENCECOUNTEDARRAY_H_INCLUDED
 
#include "../memory/ReferenceCountedObject.h"
 
namespace water {
 
//==============================================================================
template <class ObjectClass>
class ReferenceCountedArray
{
public:
    typedef ReferenceCountedObjectPtr<ObjectClass> ObjectClassPtr;
 
    //==============================================================================
    ReferenceCountedArray() noexcept
        : numUsed (0)
    {
    }

    ReferenceCountedArray (const ReferenceCountedArray& other) noexcept
    {
        numUsed = other.size();
        data.setAllocatedSize (numUsed);
        memcpy (data.elements, other.getRawDataPointer(), (size_t) numUsed * sizeof (ObjectClass*));
 
        for (int i = numUsed; --i >= 0;)
            if (ObjectClass* o = data.elements[i])
                o->incReferenceCount();
    }

    template <class OtherObjectClass>
    ReferenceCountedArray (const ReferenceCountedArray<OtherObjectClass>& other) noexcept
    {
        numUsed = other.size();
        data.setAllocatedSize (numUsed);
        memcpy (data.elements, other.getRawDataPointer(), numUsed * sizeof (ObjectClass*));
 
        for (int i = numUsed; --i >= 0;)
            if (ObjectClass* o = data.elements[i])
                o->incReferenceCount();
    }

    ReferenceCountedArray& operator= (const ReferenceCountedArray& other) noexcept
    {
        ReferenceCountedArray otherCopy (other);
        swapWith (otherCopy);
        return *this;
    }

    template <class OtherObjectClass>
    ReferenceCountedArray<ObjectClass>& operator= (const ReferenceCountedArray<OtherObjectClass>& other) noexcept
    {
        ReferenceCountedArray<ObjectClass> otherCopy (other);
        swapWith (otherCopy);
        return *this;
    }

    ~ReferenceCountedArray()
    {
        releaseAllObjects();
    }
 
    //==============================================================================
    void clear()
    {
        releaseAllObjects();
        data.setAllocatedSize (0);
    }

    void clearQuick()
    {
        releaseAllObjects();
    }

    inline int size() const noexcept
    {
        return numUsed;
    }

    inline bool isEmpty() const noexcept
    {
        return size() == 0;
    }

    inline ObjectClassPtr operator[] (const int index) const noexcept
    {
        return getObjectPointer (index);
    }

    inline ObjectClassPtr getUnchecked (const int index) const noexcept
    {
        return getObjectPointerUnchecked (index);
    }

    inline ObjectClass* getObjectPointer (const int index) const noexcept
    {
        if (isPositiveAndBelow (index, numUsed))
        {
            wassert (data.elements != nullptr);
            return data.elements [index];
        }
 
        return ObjectClassPtr();
    }

    inline ObjectClass* getObjectPointerUnchecked (const int index) const noexcept
    {
        wassert (isPositiveAndBelow (index, numUsed) && data.elements != nullptr);
        return data.elements [index];
    }

    inline ObjectClassPtr getFirst() const noexcept
    {
        if (numUsed > 0)
        {
            wassert (data.elements != nullptr);
            return data.elements [0];
        }
 
        return ObjectClassPtr();
    }

    inline ObjectClassPtr getLast() const noexcept
    {
        if (numUsed > 0)
        {
            wassert (data.elements != nullptr);
            return data.elements [numUsed - 1];
        }
 
        return ObjectClassPtr();
    }

    inline ObjectClass** getRawDataPointer() const noexcept
    {
        return data.elements;
    }
 
    //==============================================================================
    inline ObjectClass** begin() const noexcept
    {
        return data.elements;
    }

    inline ObjectClass** end() const noexcept
    {
        return data.elements + numUsed;
    }
 
    //==============================================================================
    int indexOf (const ObjectClass* const objectToLookFor) const noexcept
    {
        ObjectClass** e = data.elements.getData();
        ObjectClass** const endPointer = e + numUsed;
 
        while (e != endPointer)
        {
            if (objectToLookFor == *e)
                return static_cast<int> (e - data.elements.getData());
 
            ++e;
        }
 
        return -1;
    }

    bool contains (const ObjectClass* const objectToLookFor) const noexcept
    {
        ObjectClass** e = data.elements.getData();
        ObjectClass** const endPointer = e + numUsed;
 
        while (e != endPointer)
        {
            if (objectToLookFor == *e)
                return true;
 
            ++e;
        }
 
        return false;
    }

    ObjectClass* add (ObjectClass* const newObject) noexcept
    {
        data.ensureAllocatedSize (numUsed + 1);
        wassert (data.elements != nullptr);
        data.elements [numUsed++] = newObject;
 
        if (newObject != nullptr)
            newObject->incReferenceCount();
 
        return newObject;
    }

    ObjectClass* insert (int indexToInsertAt,
                         ObjectClass* const newObject) noexcept
    {
        if (indexToInsertAt < 0)
            return add (newObject);
 
        if (indexToInsertAt > numUsed)
            indexToInsertAt = numUsed;
 
        data.ensureAllocatedSize (numUsed + 1);
        wassert (data.elements != nullptr);
 
        ObjectClass** const e = data.elements + indexToInsertAt;
        const int numToMove = numUsed - indexToInsertAt;
 
        if (numToMove > 0)
            memmove (e + 1, e, sizeof (ObjectClass*) * (size_t) numToMove);
 
        *e = newObject;
 
        if (newObject != nullptr)
            newObject->incReferenceCount();
 
        ++numUsed;
 
        return newObject;
    }

    bool addIfNotAlreadyThere (ObjectClass* const newObject) noexcept
    {
        if (contains (newObject))
            return false;
 
        add (newObject);
        return true;
    }

    void set (const int indexToChange,
              ObjectClass* const newObject)
    {
        if (indexToChange >= 0)
        {
            if (newObject != nullptr)
                newObject->incReferenceCount();
 
            if (indexToChange < numUsed)
            {
                if (ObjectClass* o = data.elements [indexToChange])
                    releaseObject (o);
 
                data.elements [indexToChange] = newObject;
            }
            else
            {
                data.ensureAllocatedSize (numUsed + 1);
                wassert (data.elements != nullptr);
                data.elements [numUsed++] = newObject;
            }
        }
    }

    void addArray (const ReferenceCountedArray<ObjectClass>& arrayToAddFrom,
                   int startIndex = 0,
                   int numElementsToAdd = -1) noexcept
    {
        if (startIndex < 0)
        {
            wassertfalse;
            startIndex = 0;
        }
 
        if (numElementsToAdd < 0 || startIndex + numElementsToAdd > arrayToAddFrom.size())
            numElementsToAdd = arrayToAddFrom.size() - startIndex;
 
        if (numElementsToAdd > 0)
        {
            data.ensureAllocatedSize (numUsed + numElementsToAdd);
 
            while (--numElementsToAdd >= 0)
                add (arrayToAddFrom.getUnchecked (startIndex++));
        }
    }

    template <class ElementComparator>
    int addSorted (ElementComparator& comparator, ObjectClass* newObject) noexcept
    {
        const int index = findInsertIndexInSortedArray (comparator, data.elements.getData(), newObject, 0, numUsed);
        insert (index, newObject);
        return index;
    }

    template <class ElementComparator>
    void addOrReplaceSorted (ElementComparator& comparator,
                             ObjectClass* newObject) noexcept
    {
        const int index = findInsertIndexInSortedArray (comparator, data.elements.getData(), newObject, 0, numUsed);
 
        if (index > 0 && comparator.compareElements (newObject, data.elements [index - 1]) == 0)
            set (index - 1, newObject); // replace an existing object that matches
        else
            insert (index, newObject);  // no match, so insert the new one
    }

    template <class ElementComparator>
    int indexOfSorted (ElementComparator& comparator,
                       const ObjectClass* const objectToLookFor) const noexcept
    {
        ignoreUnused (comparator);
        int s = 0, e = numUsed;
 
        while (s < e)
        {
            if (comparator.compareElements (objectToLookFor, data.elements [s]) == 0)
                return s;
 
            const int halfway = (s + e) / 2;
            if (halfway == s)
                break;
 
            if (comparator.compareElements (objectToLookFor, data.elements [halfway]) >= 0)
                s = halfway;
            else
                e = halfway;
        }
 
        return -1;
    }
 
    //==============================================================================
    void remove (const int indexToRemove)
    {
        if (isPositiveAndBelow (indexToRemove, numUsed))
        {
            ObjectClass** const e = data.elements + indexToRemove;
 
            if (ObjectClass* o = *e)
                releaseObject (o);
 
            --numUsed;
            const int numberToShift = numUsed - indexToRemove;
 
            if (numberToShift > 0)
                std::memmove (e, e + 1, sizeof (ObjectClass*) * (size_t) numberToShift);
 
            if ((numUsed << 1) < static_cast<int>(data.numAllocated))
                minimiseStorageOverheads();
        }
    }

    ObjectClassPtr removeAndReturn (const int indexToRemove)
    {
        ObjectClassPtr removedItem;
 
        if (isPositiveAndBelow (indexToRemove, numUsed))
        {
            ObjectClass** const e = data.elements + indexToRemove;
 
            if (ObjectClass* o = *e)
            {
                removedItem = o;
                releaseObject (o);
            }
 
            --numUsed;
            const int numberToShift = numUsed - indexToRemove;
 
            if (numberToShift > 0)
                memmove (e, e + 1, sizeof (ObjectClass*) * (size_t) numberToShift);
 
            if ((numUsed << 1) < data.numAllocated)
                minimiseStorageOverheads();
        }
 
        return removedItem;
    }

    void removeObject (ObjectClass* const objectToRemove)
    {
        remove (indexOf (objectToRemove));
    }

    void removeRange (const int startIndex,
                      const int numberToRemove)
    {
        const int start    = jlimit (0, numUsed, startIndex);
        const int endIndex = jlimit (0, numUsed, startIndex + numberToRemove);
 
        if (endIndex > start)
        {
            int i;
            for (i = start; i < endIndex; ++i)
            {
                if (ObjectClass* o = data.elements[i])
                {
                    releaseObject (o);
                    data.elements[i] = nullptr; // (in case one of the destructors accesses this array and hits a dangling pointer)
                }
            }
 
            const int rangeSize = endIndex - start;
            ObjectClass** e = data.elements + start;
            i = numUsed - endIndex;
            numUsed -= rangeSize;
 
            while (--i >= 0)
            {
                *e = e [rangeSize];
                ++e;
            }
 
            if ((numUsed << 1) < data.numAllocated)
                minimiseStorageOverheads();
        }
    }

    void removeLast (int howManyToRemove = 1)
    {
        if (howManyToRemove > numUsed)
            howManyToRemove = numUsed;
 
        while (--howManyToRemove >= 0)
            remove (numUsed - 1);
    }

    void swap (const int index1,
               const int index2) noexcept
    {
        if (isPositiveAndBelow (index1, numUsed)
             && isPositiveAndBelow (index2, numUsed))
        {
            std::swap (data.elements [index1],
                       data.elements [index2]);
        }
    }

    void move (const int currentIndex,
               int newIndex) noexcept
    {
        if (currentIndex != newIndex)
        {
            if (isPositiveAndBelow (currentIndex, numUsed))
            {
                if (! isPositiveAndBelow (newIndex, numUsed))
                    newIndex = numUsed - 1;
 
                ObjectClass* const value = data.elements [currentIndex];
 
                if (newIndex > currentIndex)
                {
                    memmove (data.elements + currentIndex,
                             data.elements + currentIndex + 1,
                             sizeof (ObjectClass*) * (size_t) (newIndex - currentIndex));
                }
                else
                {
                    memmove (data.elements + newIndex + 1,
                             data.elements + newIndex,
                             sizeof (ObjectClass*) * (size_t) (currentIndex - newIndex));
                }
 
                data.elements [newIndex] = value;
            }
        }
    }
 
    //==============================================================================
    template <class OtherArrayType>
    void swapWith (OtherArrayType& otherArray) noexcept
    {
        data.swapWith (otherArray.data);
        std::swap (numUsed, otherArray.numUsed);
    }
 
    //==============================================================================
    bool operator== (const ReferenceCountedArray& other) const noexcept
    {
        if (numUsed != other.numUsed)
            return false;
 
        for (int i = numUsed; --i >= 0;)
            if (data.elements [i] != other.data.elements [i])
                return false;
 
        return true;
    }

    bool operator!= (const ReferenceCountedArray<ObjectClass>& other) const noexcept
    {
        return ! operator== (other);
    }
 
    //==============================================================================
    template <class ElementComparator>
    void sort (ElementComparator& comparator,
               const bool retainOrderOfEquivalentItems = false) const noexcept
    {
        ignoreUnused (comparator); // if you pass in an object with a static compareElements() method, this
                                   // avoids getting warning messages about the parameter being unused
 
        sortArray (comparator, data.elements.getData(), 0, size() - 1, retainOrderOfEquivalentItems);
    }
 
    //==============================================================================
    void minimiseStorageOverheads() noexcept
    {
        data.shrinkToNoMoreThan (numUsed);
    }

    void ensureStorageAllocated (const int minNumElements)
    {
        data.ensureAllocatedSize (minNumElements);
    }
 
private:
    //==============================================================================
    ArrayAllocationBase <ObjectClass*> data;
    int numUsed;
 
    void releaseAllObjects()
    {
        while (numUsed > 0)
            if (ObjectClass* o = data.elements [--numUsed])
                releaseObject (o);
 
        wassert (numUsed == 0);
    }
 
    static void releaseObject (ObjectClass* o)
    {
        if (o->decReferenceCountWithoutDeleting())
            delete o;
    }
};
 
}
 
#endif // WATER_REFERENCECOUNTEDARRAY_H_INCLUDED